A hydrogen flame does emit considerable ultraviolet light (UV), and that's the basis of most hydrogen flame detectors, which detect UV light below a wavelength of 300 nm. The 300 nm wavelength cutoff is critical, since ultraviolet radiation from the Sun would trigger these detectors in the absence of a flame (see figure).

A better solar-blind option than using a broadband UV detector with a filter is to make a detector that responds only to the intended wavelengths. As shown in the figure, the threshold wavelength for optical absorption can be tuned in some materials such that the only response will be at solar-blind wavelengths.